#include <iostream>
#include <cstdlib>
#include <string>
#include <vector>

int main()
{
    std::string s;
    std::cin >> s;
    for(auto i = s.begin(); i != s.end(); i++){
        char c = *i;
        unsigned int u = c;
        if(u < 90){
            u += 32;
        } else {
            u -= 32;
        }
        c = u;
        std::cout << c;
    }
    std::cout << std::endl;
    return 0;
}